#37902: Sir Arthur Streeb-Greebling — 08/29  at  10:22 AM

Surely you are not saying that genetic differences between humans have an effect on their cognitive abilities, which in turn have important consequences on how their lives will turn out? Because that is one very big and bad no-no to be saying these days.

Genetic differences are bound to effect all organs of the body, including the brain, and mental abilities will be influenced to some extent. We don't really know the details of this yet, but as time goes on it will become better understood.

I think you are confusing some notions of equality between people. There is one type of equality, where all people are supposed to be treated with equal fairness under the law, and there is the other kind of equality where people have the same genes (identical twins).

Of course people aren't only products of their genes, they're also products of society which is a sort of secondary inherritance. I know people who live in very poor areas, and you can see that their children are born with immediate tangible dissadvantages relative to their peers - regardless of how good or bad their genes are.

#37905: — 08/29  at  10:36 AM
jaimito:

you are wrong thinking that these efforts are effective. They are not.

In theory, everyone may have the number of children he or she wants (within physiological possibilities) and the children's survival is ensured. In reality, almost no one is exploiting this unprecedented opportunity. When 20 -30% of the people has zero success in reproduction, and when another 50% fails to achieve the 2.2 children required for self-replacement, we have to conclude that having children in our society is VERY difficult and therefore, the effective selective pressure is higher than experienced by former generations.

Why having children is so difficult? Many think it is a voluntary, personal decision, but of course, statistically it is not. If I knew the answer, I would sell it to the French, who for the last 100 years are trying to increase (French) natality, with no great success.

Actually, research suggests that the drop in birth rates in developed countries is almost solely cultural. For instance, in the US, the rate of birth correlates inversely with socioeconomic status. The lower your SES, the more children you are likely to have. This is contrary to normal genetic factors, which would suggest that the subpopulation with greater resources would be more successful in reproduction. Infertility is part of the equation, but the medical success for infertility treatment is quite high, especialy for people of higher SES. As such, the logical conclusion is that a culturally-based decision is behind the lagging birth rates in educated and wealthy countries is behind the drop.

My point was that genetic selection has been largely abrogated by societal effects. Evidence for the success in this abrogation is widespread. I don't know the actual statistics, but a large percentage of the population has vision impairment, moderate to severe allergies, asthma, diabetes, etc. Most of these diseases would be debilitating or fatal in a non-technological society. The fact that someone in our modern society can successfully reproduce at approximately the same rate as a completely healthy individual of the same culture demonstrates that genetic selection has eased.

As such, the largest part of the selection we see is the effects of social selection, not genetic selection. Some cultures that represent sub-populations have more reproductive success, but members of this culture are not greatly limited by their genetic fitness (which is largely alleviated by technology) but by their cultural adherence. My question/concern is that the lack of selection for people more fit genetically should be reducing the genetic fitness of the population.

#37906: — 08/29  at  10:48 AM
Sir Arthur Streeb-Greebling: "I think you are confusing some notions of equality between people."

No, I am asking how the notions of (1) ongoing human evolution and (2) genetic equivalence of all humans (not identical equality or moral equality, but functional equivalence in the sense that it doesn't really matter what genes you get, since the effect of genes to your phenotype is pretty much irrelevant when compared to nurture and environment) can possibly be combined, since evolution by selection seems to require that there are important genetic differences between individuals.

I am asking this because a highly nontrivial number of people currently seem to believe both (1) and (2). In many places around the blogosphere, saying something like "Genetic differences are bound to effect all organs of the body, including the brain, and mental abilities will be influenced to some extent. We don't really know the details of this yet, but as time goes on it will become better understood" would be met with a very negative response.

"Of course people aren't only products of their genes, "

Which is why I wrote that genes have an effect, not that they fully determine how one turns out. But this effect has got to be at least relevant for the natural selection to work on it.

#37926: — 08/29  at  01:20 PM
Appleyard is essentially a print-media troll. His stock-in-trade is factually-deficient 'common-sense' contrarianism. One highlight from 2001: "Nobody, twenty years ago, predicted the Internet." Apart from those using it at the time, one presumes.

#37928: — 08/29  at  01:27 PM
Shygetz,

".. medical success for infertility treatment is quite high.." Actually, after 30, is very low.

Very low SES people rarely reproduce.

Regarding the reduction of genetic fitness you find worrying, I think humanity will never live again in the environment where evolved, the African savanna. Therefore, genetic fitness to succeed in the savanna is meaningless.

#37936: — 08/29  at  02:10 PM

My question/concern is that the lack of selection for people more fit genetically should be reducing the genetic fitness of the population.

"Genetic fitness" is not a universal. It depends on the environment(s) in which a population lives. Environments change unpredictably. The closest thing to a generic "genetic fitness" would be genetic diversity. Regardless, in my opinion it should not be the business of society to engineer genetic fitness excepting the obvious cases where specific harm is likely, such as incest.Cheers,
Craig

#38029: Alon Levy — 08/30  at  12:33 AM
Very low SES people rarely reproduce.

Who are these very low SES people and how many of them are there? For instance, I presume someone who's homeless isn't likely to reproduce, but there aren't many homeless people, and the bulk of low SES people seem to be reproducing just fine.

My question/concern is that the lack of selection for people more fit genetically should be reducing the genetic fitness of the population.

If you look at what actually happens, you'll see that this is not the case. In particular, look at IQ, eugenicists' favorite heritable trait. IQ is extremely heritable - for people from the middle class up, its heritability is 0.72 and as far as I know there are no widespread environmental factors affecting it. For low SES people the heritability drops to 0.1 because of environmental problems such as racism and lack of linguistic stimulation, but still there is an underlying genetic capacity with heritability of 0.72 because acquired traits are not genetically inherited. If indeed there was dysgenics occurring because of the lack of selection pressure, we'd see IQ stay constant, or at best rise a few points from its WW2 level and then level off. In fact, in the last six decades IQ has constantly risen by about 3% per decade in the USA and Sweden, the only two countries people have published researches I know of about.

#38033: — 08/30  at  03:27 AM
Alon,

Who are these very low SES people?

The village idiot? Madonna's Kabbala water consumers? Buyers of Russian tzarist bonds? BTW, how can SES's IQ heritability drop to 0.1 in certain environments? I see. SES are so careless, once myself almost saw a SES dropping an antique heritability porcelain figurine.

#38035: Alon Levy — 08/30  at  04:45 AM
The village idiot? Madonna's Kabbala water consumers? Buyers of Russian tzarist bonds?

Are they really low SES, or just low IQ and high gullibility?

BTW, how can SES's IQ heritability drop to 0.1 in certain environments?

Go to my Lewontin article on UTI Annex; toward the end there's a link to a study that concludes that IQ's genetic heritability is 0.72 for people of medium or high SES but only 0.1 for people of low SES. The obvious explanation is that IQ is very strongly genetically inheritable, but certain environmental effects associated with poverty can reduce it.

#38050: — 08/30  at  07:11 AM
You may be reassured to learn that the BBC is working on a series intended to commemorate the 150th anniversary of the publication of On the Origin of Species in 2009 as reported here: http://news.independent.co.uk/media/article308891.ece

...and we still have Darwin on our money.

#38053: — 08/30  at  07:30 AM
IQ is a terrible quantitative trait to base a conclusion on, because even the psychologists can't agree on what it means. Also, IQ is known to be easily changed by education (not much, but a statistical amount), and the current tests are thought by some to be biased by SES. Believe me, my wife is a researcher that helps develop those kinds of tests, and we talk about it often. While I never said that directional evolution of all heritable traits was being abrogated, I suggest that many are not being selected strongly if at all. I am also suggesting that many of the mutations that are accumulating in the population are detrimental even in the current environment (visual impairment, haemophilia, diabetes, etc.), but that society has done such an excellent job in eliminating selective pressure that the detrimental mutations propogate at about the same rate as the non-detrimental mutations. One thing I did not mention is that, in low SES cultures, many of these phenotypes are strongly selected against, while in high SES cultures they are not.

Regarding the reduction of genetic fitness you find worrying, I think humanity will never live again in the environment where evolved, the African savanna. Therefore, genetic fitness to succeed in the savanna is meaningless.

"Genetic fitness" is not a universal. It depends on the environment(s) in which a population lives. Environments change unpredictably. The closest thing to a generic "genetic fitness" would be genetic diversity. Regardless, in my opinion it should not be the business of society to engineer genetic fitness excepting the obvious cases where specific harm is likely, such as incest.

Ridiculous. Many of the examples I am giving are not for fitness in the savannah, they are for general fitness in almost all environments, including the current one. Blindness is not an adaptive trait in a species that can close its eyes. If you cannot imagine a situation where humanity would be without the benefit of advanced technology, then I suggest you read more speculative fiction, or just look at geological history. Global catastrophes are almost a given even from natural causes, and now we have new and different ways of causing global catastrophes ourselves. And if you have a population that is not fit and it undergoes a severe increase in selective pressure, you can observe enormous population crashes and extinctions. I don't want to put on the tin-foil hat here, but shouldn't we at least be asking if the constant abrogation of selective pressure for many traits is in the best long term interest of humanity? And if not, should some measures be taken to replace this selection in clear-cut cases of deleterious mutation (i.e. germ line gene therapy)?

#38062: Alon Levy — 08/30  at  08:27 AM
I don't want to put on the tin-foil hat here, but shouldn't we at least be asking if the constant abrogation of selective pressure for many traits is in the best long term interest of humanity?

First you need to show that these traits are becoming more common. Just claiming that logically they should isn't enough, because logically despite increased levels of education, the average IQ should be going down or at least remaining constant (presumably differences in education levels of 7-year-old middle class kids are small enough to have entirely skipped the study I'm referring to).

#38074: — 08/30  at  08:58 AM

presumably differences in education levels of 7-year-old middle class kids are small enough to have entirely skipped the study I'm referring to

Terrible presumption. The early years of development are thought (and to some extent, known) to be highly important for cognitive development. 7 years old is after a large bulk of this cognitive development. In addition, as I said earlier, it is not known what IQ tests measure (other than the ability to take IQ tests), so trying to decide how and if IQ is subject to selective pressure is an exercise in futility until the ability to take IQ tests becomes a survival factor.

First you need to show that these traits are becoming more common. Just claiming that logically they should isn't enough

Ridiculous. Given that you acknowledge evolution, then all I need to show is that the reproductive success of people with these traits has increased over time; it can then be inferred that the frequency of the allele(s) involved will increase in the population.

While I don't have the reproduction or allelic/phenotypic frequencies at hand (I am currently at home, not work), I can give statistics for hemophilia that strongly suggest that their reproductive success has increased as a function of time. From http://www.accredohealth.net/hhs/bleeding_disorders/hemophilia_stats.html

Average Life Expectancy For People With Hemophilia
Prior to World War II 11 years old
Prior to 1968 20 years old
1968 less than 40 years old
1983 64 years
1988 40 years (decrease due to impact of AIDS on community)
1999 normal life span

Now, given that in the course of about 60-70 years, the average life expectency has increased from pre-pubescent to a normal life-span, it is not a stretch to assume that the reproductive success of hemophiliacs has increased dramatically due to societal factors. From such an assumption, one can infer that the allelic frequency of hemophilia has increased very substantially over the last 70 years. As such, the selective pressure against hemophilia has been abrogated to a large extent. There are numerous other examples of similar diseases/disorders with genetic factors that are no longer selected against as strongly. So, my question stands.

#38085: Alon Levy — 08/30  at  10:50 AM
Ridiculous. Given that you acknowledge evolution, then all I need to show is that the reproductive success of people with these traits has increased over time; it can then be inferred that the frequency of the allele(s) involved will increase in the population.

It's not so clear. Stephen J. Gould railed against precisely this attitude of presuming that something is adaptive without evidence, and he wasn't exactly a creationist. For the hemophilia example, it's possible that although the life expectancy of hemophiliacs has increased, women's willingness to abort hemophiliac fetuses has countered that. Alternatively, we can use the fact that hemophiliacs' life expectancy is increasing to argue that hemophilia is no longer maladaptive because of medical treatment, and therefore there's no reason to get up about a possible increase in the frequency of the hemophilia-causing allele.

#38088: — 08/30  at  11:45 AM
To quote Shygetz, Ridiculous!

The obvious explanation is that IQ is very strongly genetically inheritable, but certain environmental effects associated with poverty can reduce it.

My parents were very very poor. During the war, my father was a slave in the Bor copper mines and later worked as laborer in a construction block factory. Little to eat for many years. My mother still lives from social security. They didn't finish high school. Should I worry about DNA damage?

#38095: — 08/30  at  12:52 PM

For the hemophilia example, it's possible that although the life expectancy of hemophiliacs has increased, women's willingness to abort hemophiliac fetuses has countered that.

In order to believe that, you must believe that the frequency of a woman carrying a hemophiliac fetus who elects to have an abortion is equal to the frequency of hemophiliacs having children prior to WW2. As a large majority of women do not have an amniocentesis or other fetal genetic testing, this is impossible. The allelic frequency of hemophilia (and a large number of other disorders) is increasing.

And the fact that hemophilia (and other diseases) are not maladaptive in the current environment is completely my point! The lack of selective pressure on hemophiliacs is due to our manipulation of the environment. Even in the current environment, it is a maladaptive trait that requires significant resources to treat; it is just not maladaptive enough (given our abundance of resources) to eliminate the allele. My point is that, given the probability of a catastrophe that will disrupt society occuring at some point, is it a wise decision to allow the accumulation of so many maladaptive alleles that require significant resources to alleviate, given that these resources will not always be available?

#38096: Alon Levy — 08/30  at  12:54 PM

For low SES people the heritability drops to 0.1 because of environmental problems such as racism and lack of linguistic stimulation, but still there is an underlying genetic capacity with heritability of 0.72 because acquired traits are not genetically inherited.

The underlying genetic capacity is completely unrelated to environmental effects. The environmental effects associated with poverty reduce the actual IQ, not the genetic capacity.


By the way, Down Syndrome is a good counterexample for Shygetz's argument, because although the life expectancy of people suffering from it has dramatically increased, prenatal diagnosis has led to a very high rate of abortion of fetuses with trisomy, so the prevalence of the disorder in the population is lower than it was in the past.

#38100: Alon Levy — 08/30  at  01:16 PM
My point is that, given the probability of a catastrophe that will disrupt society occuring at some point, is it a wise decision to allow the accumulation of so many maladaptive alleles that require significant resources to alleviate, given that these resources will not always be available?

That probability is so vanishingly low that we need not worry about it. In any case, if suddenly some trait becomes maladaptive again, it will disappear on its own because of Darwinian evolution. For example, if HIV mutates to a virus that combines AIDS's difficulty of treatment with the virulence of the bubonic plague, then we'll naturally see the frequency of the allele conferring immunity to both HIV and the bubonic plague skyrocket.

#38116: — 08/30  at  02:48 PM

By the way, Down Syndrome is a good counterexample for Shygetz's argument, because although the life expectancy of people suffering from it has dramatically increased, prenatal diagnosis has led to a very high rate of abortion of fetuses with trisomy, so the prevalence of the disorder in the population is lower than it was in the past.

This in no way invalidates my point. I did not say that we can treat every genetic malady. Only that the fact that we can treat many of them has led to their increasing frequency in the population, to the detriment of our genetic fitness. And the reproductive success of Down's syndrome victims has neither risen nor fallen; it remains about zero.

That probability global catastrophe is so vanishingly low that we need not worry about it.

Given enough time, the probability approaches one, as with any possible event. What should be done about it? Should we allow maladaptations to accumulate just because we presently have the resources to deal with them?

The underlying genetic capacity is completely unrelated to environmental effects. The environmental effects associated with poverty reduce the actual IQ, not the genetic capacity.

Pointless argument. Of course, by definition, the genetic component of any trait is unaffected by environment. But the heritability of a trait as heavily affected by environment and as amorphous as IQ cannot be reliably determined. The fact is, no one can quantitate how much IQ is affected by environment. IQ measurements cannot be reproduced, as you cannot give the same subject the same test and get the same result (known as the practice effect in cognitive testing). The community cannot agree on the presence of bias in the test towards different cultures. The genetic components of IQ are unknown, as are the environemntal components. The actual adaptive effect of IQ is not known. IQ is a terrible quantitative trait for genetic analysis. One would be better measuring height or blood pH or something more readily quantitated.

#38166: — 08/30  at  10:23 PM

given the probability of a catastrophe that will disrupt society occuring at some point, is it a wise decision to allow the accumulation of so many maladaptive alleles?

There are no old questions, only young people. For a newborn, all questions are new. So, are we going to start debating eugenics?Or maybe it's an example of absurdist British humor...? (The title of this thread).

#38184: — 08/31  at  05:27 AM
<blockquote>So, are we going to start debating eugenics?(/blockquote>

I think that would be a bad idea for many reasons. First of all, as you (perhaps unintentionally) pointed out, human eugenics has a bad history and terrible PR. But, it is also a terribly inefficient and, historically, amoral way to do things.

I am thinking about germ line gene therapy, not eugenics. And I think that it is a topic that should be debated (although perhaps not in this thread). My original point in the context of this thread is that, while evolution for humans has not stopped, it has been drastically effected by our ubiquitous alteration of our environment, making us highly dependent on an artificial environment that requires abundant resources to maintain.